<!DOCTYPE html>
<html>
<head>
	<title></title>
</head>
<body>

<style>
.injected-text {
margin-bottom: -25px;
text-align: center;
}

.box {
border-style: solid;
border-color: black;
border-width: 5px;
text-align: center;
}

.yellow-box {
background-color: yellow;
padding: 20px 40px 20px 40px;
}

.red-box {
background-color: red;
margin: 20px 40px 20px 40px;
}

.green-box {
background-color: green;
margin: 40px 20px 20px 40px;
}
</style>
<h5 class="injected-text">margin</h5>

<div class="box yellow-box">
<h5 class="box red-box">padding</h5>
<h5 class="box green-box">padding</h5>
</div>

</body>
</html>